midi

As part of NZ Music Month I was invited to play in the Dunedin Public Library. Because I love libraries, and this one (a marvellous concrete construction) in particular, I jumped at the chance! And of course I'm generally obsessed with the idea of playing electronic music live.

Cue a month or so of fervent anxious work getting a set together. Because this was a 20 minute slot, I felt that I could pull out all the stops and make this as complicated as I wanted. Over the last wee while I've been making lots of little loops so I had a bunch of material to play with.

The first time through (I had two slots booked - a Sunday morning and a Thursday after work), I had a technical problem, and had to play a (boring old, not even live mate) DJ set instead. In the intervening time I dusted off a custom nodejs websockets OSC UI thing to replace the bits that didn't work (studiomux providing OSC-over-lightning cable). This worked great, turning the iPad into a wireless pattern-trigger controller.

On the laptop I used SuperCollider as a MIDI pattern sequencer and also to play back texture samples. This all fed into Logic Pro X where the synthesis, effects and mix happened (with lots of params assigned to hardware knobs).

Here's the recording - great background music for reading perhaps? Hope it's as much fun to listen to as it was to put together :)

In Traktor, open the sync panel thing up the top by clicking the metronome.

Click "EXT" button - this tells traktor to listen for MIDI Clock.

Now get a track (with an accurate grid!) loaded into a Traktor deck. In Reaper, set up something locked to the Reaper beat grid - for example, an audio or midi loop.

Press play in Reaper so your loop plays forever. In Traktor, the sync panel should show a tempo similar to the tempo in Reaper. You'll notice that it wavers about a bit. Press play on your gridded track and click Sync.

The Traktor deck should be roughly in sync with Reaper! (In fact, it is loose enough that it sounds a bit like a real DJ is nudging it.)

Questions:

If we send the MIDI over a network or MIDI connection to a different machine, will this sync well enough to bother with?

Can we sync two copies of Traktor (on different machines) this way?

If you have problems (or corrections), comment below so we can determine what I really did to make this work.

So the picture is almost self-explanatory. The container lid is drilled with 4x4x2 holes (I bent the 1mm drill bit, so the first 2 holes are 1mm, the rest 1.5mm). The LEDs are inserted, all facing the same direction (oriented so the flat, negative side of each LED is on the same side!). The legs are then bent and soldered together horizontally, and then vertically. In between, I taped (masking tape!) over the previous soldered connections as a crude insulator.

Then I tested it with the multimeter (also a gift from my bro, but one that I got to build myself (with the soldering iron he gave me!)). Handily, the test current from the meter actually lights the LEDs up, which is great for "it's now lights out time, stop reading please" demonstrations to kids (at about 8.10 pm at our house).

Needless to say it works perfectly.

What next for my LED matrix?

Well, about a year ago I bought a whole lot of electronics components for my planned (predicted? hypothetical) USB-MIDI controller project. So the plan is to try driving the LEDs (simple strobed animations, etc) from an AVR brain through two 4051 multiplexers. I don't know much about how to do this but I will learn! Hopefully this will be then form a good light-up part for underneath a 4x4 button array in this supposed controller...